No MQA first unfold

Core Machine (Operating system/System info/Roon build number)

ROCK latest

Network Details (Including networking gear model/manufacturer and if on WiFi/Ethernet)

Ethernet

Audio Devices (Specify what device you’re using and its connection type - USB/HDMI/etc.)

Pi 4 and USB out
Realtek sound card on Win 7 laptop

(separate zones)

Description Of Issue

I have one MQA album. It is “Fairytales” by Radka Toneff, a MQA CD that authenticates to 24/176.4. Roon authenticates it but does not do the first unfold (or Signal Path does not show the unfold)
I have just started using ROCK and I seem to remember that my previous core (running on a Debian install) displayed this.

Hi @ogs

Can you share a screenshot of the MQA settings in Device Setup as well as a screenshot of the Signal Path?

Thanks!

Do not use Realtek for this test. Some Realtek chips do not support 88.2kHz so it is impossible for MQA Core decoding, even though they may support 192kHz.

Use only a USB DAC - set its MQA capabilities to No MQA Support.

Make sure Roon MQA Core decoder is enabled.

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Problem is there is nowhere to set the Roon Core decoder. It’s gone! Where should it be?

Ah, it is in Device setup->Advanced, but not for the DAC I use. This DAC handshakes 48kHz with RoPieee. I’ve set Sample rate conversion in DSP to handle this. Is Roon hiding settings for MQA core decoder because the DAC reports 48kHz? It was not like this earlier. Also, re-sampling took place after MQA first unfold so the DAC would receive PCM based on its capabilities.
And for some reason Roon is not showing the first unfold in Signal path any more. Why? All conversions of PCM and DSD are still there…

Some more testing on this. Even if Roon authenticates the MQA as 176.4 it plays the 16bit file to an Android tab. I can see this because 44.1 is re-sampled by Roon to 48kHz to match the Android sound system.

Hey @ogs, can you post a screenshot of the 2nd half of your signal path?

For MQA Core decoding a DAC has to accept both 88.2kHz and 96kHz.

If you use a DAC that supports no higher than 48kHz, you do not need MQA Core decoding.

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That is not correct. Of course I need MQA encoding. Othervice Roon will, in the case of “MQA CD”, only play the 16bit 44.1kHz compressed MQA transport container, not the expanded 24bit version.

Sure. Looks like this

image

Thanks for that @ogs.

@wklie is correct here – if your DAC doesn’t support 88.2kHz or 96kHz, MQA Core decoding isn’t going to happen since your DAC will not support the resulting sample rate.

This doesn’t make sense at all.

With this policy in place you are excluding MQA for many who use their Android devices with headphones as endpoints. At least a few thousands.
And Roon has just granted Devialet Roon Ready status for the Phantom range. They are all limited to 48kHz with RAAT. So no MQA there!

If my DAC reports max 96kHz to Roon, but I select 48kHz as rate for it in Roon, Roon will happily perform MQA unfold and then re-sample because of my configuration choice?

And what about the Dutch & Dutch 8c speaker? It uses 48kHz internally and re-samples incoming streams. Then MQA will be pointless here too?

It does seem like Roon is doing unfolding. As you can see I use convolution and EQ so the stream is converted to 64bit. The line after “Authentication MQA 176.4” says “24bit to 64bit Float” while a ordinary CD rip reads “16bit to 64bit Float”. The DSP stage is obviously receiving a 24bit stream from playing the MQA file and a 16bit stream from the CD rip. Why is this?

If Roon is unfolding, why isn’t the unfold and sample rate conversion shown in Signal path?

Hello @ogs,

If my DAC reports max 96kHz to Roon, but I select 48kHz as rate for it in Roon, Roon will happily perform MQA unfold and then re-sample because of my configuration choice?

If you limit a device to 48kHz Roon will not perform the Core decoder unfold.

It does seem like Roon is doing unfolding. As you can see I use convolution and EQ so the stream is converted to 64bit. The line after “Authentication MQA 176.4” says “24bit to 64bit Float” while a ordinary CD rip reads “16bit to 64bit Float”. The DSP stage is obviously receiving a 24bit stream from playing the MQA file and a 16bit stream from the CD rip. Why is this?

You’re right, we’re showing 24-bits going into the Roon DSP stage from a 16-bit MQA file without explanation. I’ve reached out to the development team to find out what’s happening here.

-John

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This is different behaviour from earlier. Is this new in 1.8? Is it mandated by MQA(license) or has Roon decided to do it this way?

Hello @ogs,

To the best of my knowledge this behavior has not changed. I just booted a Roon 1.7 (built 571) installation to check, the behavior is the same when limiting a USB DAC to 24/48 max.

-John

MQA decoding “unfolds” 44.1 to 88.2 or 48 to 96. If your DAC cannot accept 88.2 or 96, it’s not going to work. You would need to turn off Roon core MQA decoding and use the 16/44.1 or 16/48 file or get a new DAC. Or, maybe you don’t need to turn it off, but it’s not going to do the “unfolding.”

Thanks Jim, I understand how this should work, but I have seen the unfold in Signal path. It is not there anymore. The setting for Roon core MQA decoding is also hidden.
This is not very important to me as I care little about MQA. A lot of others do though so this is a little fight for them.

The MQA settings in Roon are not hidden for me. I don’t know why this would be?

It is a long time since I looked at MQA in my system so I could easily have this wrong. Thanks for checking!